Hi neb,
Good to see you again (even though it does mean you're having a problem).
Are you using DVD+R, DVD-R, or DVD+RW disks for the backups? I see you actually used a CD-R since you posted while I was composing this. Although a bit more expensive, I recommend DVD+RW or CD+RW (assuming your Drive and burning software supports that type of media) because you can reformat them and use them again whereas the others are write
ONCE only (and eventually become essentially useless because they are too old and missing too much new data and revised information).
Also, with DVD-R and DVD+R (or the CD versions of the same), there's a difference in how the disks are made in terms of whether or not they can be used again even if the disk is not completely filled. Does the burning software close the disk and/or is it finalized? If it is finalized, nothing else can be added to the disk even if it has only used a fraction of the disk - so you would need a new disk each time unless you changed that setting (if permitted by the software).
Without further information, it is difficult to know the reason for the problem. If you did it to an 700MB CD-R, then either it did not complete or you are not backing up the entire OS (and possibly didn't even complete the files selected given that size and can't complete it since the original backup still wants more disks). If you are using Vista's backup system, then it isn't the whole OS anyway since that option isn't available in Vista Basic. See below for more information on closing the disk if that's the problem.
From the partial error message you posted, I suspect the prior backups were not properly completed somehow so the system cannot begin a new backup using that media until the prior backup is completed (it's stuck on the fact that the prior backup is not complete) - and again without knowing what you did or how you did it (can you try to explain what you did in detail and especially how it ended), it's difficult to determine why that might have occurred or how to resolve the problem. You say the original attempts were successful - how do you know that and that they were complete? Could you please provide the EXACT word-for-word error message including any codes? When you provide that information, we may be able to offer additional guidance or explanations.
Here's a general tutorial on how to do a backup that may help you identify the problem:
http://www.vista4beginners.com/How-to-backup-your-data.
The following may also help (and be sure to check out the other links usually on the right side to related articles for further information and help - and the same in those as well until you've pretty much covered the information Microsoft has to offer):
Back up and restore: frequently asked questions
http://windows.microsoft.com/en-US/windows-vista/Back-up-and-restore-frequently-asked-questions Please note the following comment in the "why can't I see the location I want to back up to" link: "
The location is a USB flash drive. You can't save backups to a flash drive." I have no idea how you presumably did this the first time, but it should not be possible unless the feature was added since the article was written and the article wasn't updated. I've not tried myself, so I'm not completely positive. Every article I've read though says the only way to do it is to copy/paste the selected files and not use the backup program (though there probably are 3rd party programs that have this ability).
If the disk is not closed (it's possible given what you provided about the error), you should be able to do so manually and this may fix the problem with that media if the prior backup did not close correctly. See the following article and go to the item on how to close a disk manually:
http://windows.microsoft.com/en-US/windows-vista/Close-or-finalize-a-CD-or-DVD. I do not know if this will work with a USB drive and am not certain I understand that problem (unless it really isn't possible as stated by the above article) - but give it a try anyway. Be sure you close it and don't finalize it or you will prevent it from being used again (that applies to disks, not the flash drive). Once done, try backing up again and see if you get the same error.
Good luck!
